Vertical Immersion Centrifugal Pump Guide

What is a Vertical Immersion Pump?

Vertical Immersion Pumps are fitted with either an extended pump or motor shaft which is encased in a column, enabling the pumping element of the pump assembly to be inserted into a tank or sump whilst the motor is kept outside of the fluid.

Vertical Immersion Pumps differ from Cantilever Centrifugal Pumps as Immersion Pumps have a separate shaft to the motor so can be supplied in lengths up to 7m, whereas Cantilever Pumps use an extended motor shaft meaning that they are limited to a maximum of 1.5m immersion length. Bearing support is provided for the pumps with longer shafts to reduce shaft deflection and ‘whipping’ of the pump in the tank. Discharge pipes for a Vertical Immersion Pump can be supplied as standard or on demand to enable an easy out of tank or sump connection to discharge pipework or hose assemblies.

Vertical Immersion Centrifugal Pump

Vertical Immersion Pump

Cantilever Pump with no bearing support

Cantilever - No Bearing Support

What is a Cantilever Pump?

Cantilever - with Bearing Support

Tapflo UK are the official UK distributors for Salvatore Robuschi, meaning we are able to supply any of their RB, RC, RD, RG or RN ISO 2858/5199 Process Centrifugal Pumps. These pumps are available in either Vertical Immersion or Cantilever configurations in a plethora of metallurgies (Cast Iron & AISI 316 as standard), as well as our CTV Cantilever pumps (SS 316, PP & PVDF). We can also offer a range of M Pumps Centrifugal Pumps, including the CNV SEAL-M, CNV MAG-M & CNV MAG-P Series.

What type of applications can Vertical Immersion Pumps be Used for?

Traditional Vertical Immersion Pump Installation in a tank

Traditional Installation in a Tank or Sump: A Vertical Immersion Pump can be operated without level controls and can run dry if the tank empties. When the fluid level in the tank rises again, the pump re-primes automatically and starts pumping again until the fluid level drops below the suction port. Maximum Immersion length is up to 6m.

Vertical Centrifugal Immersion Pump installed with suction extension pipe

Installation with a suction extension pipe:The pump operates in the same way as a traditional installation, as explained above, but has a suction depth of up to 5m.

Vertical Immersion Centrifugal Pump installed in tapered tank with solids

Installed in Tapered Tanks with Solids:Installed in a tank or sump with a tapered shape or sides leaning towards the suction of the pump. The pump can operate without level controls and completely evacuate solids whether floating or not.

Vertical Immersion Pump installed in high temperature applications

Installed in High Temperature Applications: Can be installed in tanks or sumps with process fluids up to 500ºC

Vertical Immersion Pump installed external to the tank

Installed External to Tank / Sump’s:Capable of pumping up to 300ºC in a standard configuration and 400ºC in special execution. Fitted with a by-pass for bearings lubricated by the process fluid (A).

What type of materials are available?

Tapflo can supply Vertical Immersion Pumps in the materials below, which can cater for almost any application. Get in touch with us today to find out which material would be best for you application.

- PP (GFR)


- Cast Iron

- Ductile Cast Iron


- AISI 304

- AISI 316 / CF8M

- AISI 904L

- CA6N (400 HB Hardness)

- Duplex SAF 2205

- Super Duplex SAF 2507

- Sanicro 28

- Incoloy 825

- Hastelloy C276

- Others available on request

What Performance Range can Tapflo cater for?

Tapflo UK are able to supply Vertical Immersion Centrifugal Pumps which can cover the following standard performance details, others are available on request.

Max Flow: 2200 m³/hr

Max Head: 140 m

Solids Passage:150 mm

Max Temperature: 500ºC

Max Length: 6 m

Max Discharge ø: DN250

Max Motor Power: 400 kW

Visit our Immersion Centrifugal product pages:

Stainless Steel Immersion Centrifugal Pump

PP & PVDF Immersion Centrifugal Pump

Vertical Immersion Pump

Vertical Cantilever Sump Pump

Tapflo Vertical Centrifugal Immersion Pump Case Study

Tapflo were recently approached by a customer who wanted to evacuate a 3m deep sump based on level control. The sump was being fed by a waste pipe with high temperature rinse water (98ºC) with 15% caustic. They had tried Submersible and Self-Priming Pumps in the past with little or no success.

Why were Submersible and Self-Priming Pumps not appropriate?

Submersible Pumps are generally only rated for between 40-60ºC and their electrical control cables are usually only made from H05-7RN rubber, which can be corroded and hardened by acidic and high temperature fluids. Self-Priming Pumps drastically lose their self-priming ability with temperatures over 60ºC and when close to boiling, the fluid flashes off in the suction pipe resulting in the pump running dry.

Our Solution

Tapflo offered a SS316 Seal less Immersion Pump built to the exacting sizes of the sump which was controlled via an ultrasonic level sensor positioned in a custom mounting port on the support plate of the pump. The pump, sensor and control panel with mounting stand were supplied as a complete solution package which the customer was extremely happy with due to the confidence and simplicity of the purchase.

Application Details:

Verical Centrifugal Immersion Pumps

Fluid: Hot Waste Rinse Water w/ 15% Caustic

Temperature: Up to 98ºC

Required Capacity: 30 m³/hr @ 35 m

Sump Dimensions (D x W x L): 3 x 3 x 3 m

Discharge Pipework Size: DN65 (PN16)

Motor Supply: 230-400-690V / 3 Ph / 50 Hz

Area Classification: ATEX II 2 GD IIB c T4

Pump Supplied

Model:RDV 50-16A 4B22 A 300 3

Description: Vertical Immersion, Sealless, Centrifugal Pump with Closed Impeller in A Execution (ISO 2858 / 5199 Compliant)

Fluid: Hot Rinse Water w/ 15% Caustic

Viscosity: 1.0 mm²/s

S.G: 1.0 kg/dm³

Temperature: 98ºC

Impeller ø (Rated / Min / Max): 165 / 130 / 169 mm

Rated Capacity: 30m³/hr @ 35.2 m

Absorbed Power: 5.2 kW

NPSHr: 1.4 m

Column Length: 2989.5 mm (+/- 25 mm), >120 mm clearance must be ensured between the bottom of the pit & pump suction port

Support Plate: 740 x 500 x 10 mm

Execution: A - Lubricated by pumped fluid

Discharge Connection: DN65 (PN16 - EN1092) FF

Pump Casing: Stainless Steel AISI 316

Casing Cover: Stainless Steel AISI 316

Impeller: Stainless Steel AISI 316

Wear Ring: Stainless Steel AISI 316L

Shaft: Stainless Steel AISI 316L

Shaft Sleeve: Stainless Steel AISI 316L

Bearings: Rulon J on SS Supports

Column: Stainless Steel AISI 316L

Bearing Housing: Stainless Steel AISI 316L

Bearing Housing Sealing: Viton

Support Plate: Carbon Steel

Casing Gasket: SIL C-4400

Coupling Guard: Stainless Steel AISI 304

Motor: FELM 2.2 kW / 4 Pole / 230-400V / 3 Ph / 50 Hz / IP55 / Class F / IE3 Premium Efficiency Class

Frame Size: 100L

Paint: Polyacrylic, RAL 5010

Support Plate: 740 x 500 x 10 mm

Get in contact with us today to get your hands on Tapflo’s range of Vertical Immersion Pumps!

Tel: 02380 252 325

E-Mail: [email protected]


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